''We're supposed to be going home tomorrow, but no, most people are leaving today.

''Schoolies is supposed to be holiday, it's supposed to be fun, but someone died.

"It's terrible.''

Ms Simon said her friend, who saw Isabelle fall to her death, was ''pretty shaken up''.

''He's not very good at all,'' she said.

Another schoolie, known only as Kelly, said her friend also witnessed the incident.

''One my friends was actually on our balcony when it happened ... it was just horrific,'' she said.

''They just wanted to get out. They didn't know [what] to do. She's in shock.''

Kelly said hundreds of schoolies gathered outside the Chevron towers last night, with many sitting on the ground shaking in shock, as news of the death spread rapidly via Facebook and Twitter.

''Everyone was just sitting here shaking. No one knew what was happening. It was really scary,'' she said.

''Our parents are texting us asking if it's us ... everyone just didn't know who it was or what was happening down there.

''We're just shaken up.

''I want to go home today. It's the worst.''

Condolences from school and community leaders

Mt St Michael's College principal Alison Terrey said the school community was "deeply saddened" by Isabelle's death.

"This is a tight knit community, we love our students dearly, and they know that and we are deeply saddened by what has happened in this event," she said.

"It's the worst nightmare that could possibly happen to the family. They've had three girls in the college, this was their youngest daughter. We know them very well, and please keep them in your prayers as well."

Ms Terrey said Isabelle was a "delightful young woman" who was well loved and liked by her fellow students.

"She was a class captain, so she was respected by her peers and by her teachers. She carried out those responsibilities really well. She had a great interest in photography, in drama and the creative arts, and she was hoping to continue her studies at QUT in that area."

Ms Terrey visited students still on the Gold Coast earlier today, and said they were comforting each other.

"But this is a deeply sad time for them, and the worst way schoolies could end," she said.

She also said on her return to the college, she found its reception area "flooded with flowers" from mourners.

Queensland Premier Campbell Newman urged schoolies to take care and watch our for their mates.

“It’s not a day for recrimination, what ifs and deliberations about what might have happened; it’s a day for the family to mourn,” he said.

“The Ashgrove community, the school of Mt St Michael’s, everybody is mourning today and I just want the family and friends to know that I’m thinking of them and all my team is thinking of them.

“This is a terrible day for them and indeed for everybody in the local community.”

"I just want to express my sympathy to the family and to the friends of the young teenage lady who was killed overnight," Cr Quirk said.

The lord mayor said the tragedy was a "very, very sad way" to end a week of celebration for teenagers.

"This has affected the whole of the Brisbane community and it is just so very sad to see," he said.

Death 'not suspicious'

Meanwhile, police say the teenager was alone in the unit when the incident happened and that there was no inappropriate behaviour on the balcony before the fall.

Assistant police commissioner Graham Rynders said he could not comment on whether the incident was an accident, other than to say the teenager’s death, which was witnessed by six people, was not suspicious.

He said the family of the girl was deeply traumatised and were asking for privacy.

‘‘[This has] put a very dark cloud over this schoolies,’’ he said.

Organisers offer support

Gold Coast Schoolies Advisory Group chairman Mark Reaburn said teenagers were wandering the streets of Surfers Paradise this morning looking shocked and dazed.

''Its very solemn here. You can see it with kids walking around now, it's very solemn,'' he said.

''Schoolies for the kids has turned from a celebration to a very traumatic time. It's going to be a very difficult day and night.

''We've had a lot of very traumatised kids. It's an absolute tragedy for family and friends - and it's impact across all of the kids - it's been devastating.''

Mr Reaburn said the Red Frogs chaplaincy service was counselling teenagers last night and would continue to do so throughout the day.

''Our welfare network swung into action last night,'' he said.

''We'd certainly say to parents if they're concerned for their kids by all means come and collect them, but use the welfare network that we can offer.''

Queensland police inspector Pat Swindells told reporters last night it was a horrible end to an otherwise good start to schoolies.

"Young people who've come to Surfers Paradise have been exemplary in their behaviour and this is a very tragic incident that has occurred during what has been a very good week."

Police are preparing a report for the coroner.

In the wake of the incident police are appealing for schoolies to enjoy their last night at the event safely.

This is the sixth death from a balcony fall on the Gold Coast in the past 12 months.

Earlier this week, 18-year-old Cameron Cox lying on the ledge of a Gold Coast high rise sparked renewed warnings.

- Additional reporting by Tony Moore and Natalie Bochenski

Support is available for anyone who may be distressed by calling Lifeline 131 114, Mensline 1300 789 978, Kids Helpline 1800 551 800.